import urllib


def builtwith_demo():
    res = builtwith.parse('http://example.webscraping.com')
    print(res)

def whois_website():
    print(whois.whois('baidu.com'))

def download(url):
    print("Downloading:", url)
    try:
        html = urllib.request.urlopen(url).read()
    except urllib.error.URLError as e:
        print("Download error:", e.reason)
        html = None
    return html

if __name__ == "__main__":
    # builtwith_demo()
    # whois_website()
    # download('http://dasbaidu.com')
    print("hello, world")